SBI 4U Population Dynamics
The last unit Population Dynamics (Chapter 14) will be completed as an ISU. Select a species found in
North America that is on the endangered list and use this as the model species for this assignment.
Whenever asked to provide an example of an ecological term, base it on the species you selected. For
example, if asked to define the term “habitat”, you will provide the definition and an example of a habitat.
The example you provide will be the habitat of the species you selected to research. Whenever I want you
to relate your answer to the organism you selected, I will highlight the question by bolding the text.
Likewise, your answer should be bolded when it related back to your endangered species you selected.
Endangered Organism : __________________________________
Part 1 : Characteristics of Populations
Read pages 650-658 in your textbook and then answer the following questions.
1. a) Define the word “habitat.” Provide an example.
b) Define the term “niche.” Provide an example.
c) Can two different species occupy the same niche in exactly the same area? Explain.
2. a)
In order to study populations, scientists need to be able to describe a population. What are
THREE different measurements that scientists use to describe populations
b)
Define the terms “population size” and “population density.” How do these two terms differ
from one another? Provide an example of both.
c)
Table 1 on page 651 presents the population densities for a number of species. The
statement is made “small organisms usually have higher population densities than larger
organisms”. What are TWO different reasons why you might expect this to be true?
3. a) What is meant by the term “population dispersion?” Describe the three types of dispersion
patterns. Include diagrams and an example of each type of dispersion pattern in nature.
b) What dispersion pattern does the species you selected follow?
4.
Which type of dispersion pattern is rarest in nature? Why do you think that this is the case?
5. a)
What are TWO different reasons why scientists often find it difficult to obtain an exact count of
the total number of individuals in a population?
b)
What is ONE major difference in the problems associated with obtaining measurements on the
sizes or densities of animal populations versus plant populations?
Part 2: Measuring and Modeling Population Change
Read pages 660-669 in your textbook and then answer the following questions.
1.
2.
a)
Describe some biotic resources that may be limited in an ecosystem at any one time.
b)
Describe some abiotic resources that may be limited in an ecosystem at any one time.
a)
What is meant by the term “carrying capacity of a population”?
b)
Is the carrying capacity the same for all species? Discuss.
c)
What sorts of things determine the carrying capacity of an ecosystem?
d)
In general, what happens to the resources of an ecosystem as a population increases in
size?
Define each of the following terms: natality, mortality, emigration, and immigration and
state how they affect population size.
3. a)
4.
b)
What is the formula that is used to determine “population growth” or “population
change”?
c)
A population of 2000 seals produces 950 young in one year. In the same
period of time, 150 seals die. If 50 seals leave the population to join another
population, and 30 seals join the population under study, what is the “population
change” of the population under study?
d)
What is meant by the term “fecundity”? How does it compare to the term “biotic
potential”?
a)
Do all species show the same fecundity? Provide examples of species with a high
fecundity. Provide examples of species with a low fecundity. What is the fecundity of your
organism?
b)
Compare the reproductive strategies of a short-lived species such as a starfish and a long-lived
species such as a hippopotamus. Why is there such a discrepancy in the number of offspring the
species have?
c) Sketch population growth curves that resemble geometric growth, exponential growth and
logistic growth. Under what conditions would you see each growth pattern?
d) Which type of growth (geometric, exponential or logistic) is most commonly seen in wild
populations?
5. Look at the graph below and answer the questions.
Graph 1: Rabbits Over Time
a. The graph shows a __________ growth
curve.
b. The carrying capacity for rabbits is
______
c. During which month were the rabbits in
exponential growth?
6. Human beings are largely responsible, either directly or indirectly, for the population decline of
thousands of species on the endangered list. How has human activity impacted the population
size of the species you selected? Be specific. Don’t just say pollution or habitat loss.
Read pages 671-675 in your textbook and then answer the following questions.
Factors Affecting Population Change
1.
What is a density dependent factor? List THREE different density dependent factors.
2.
Distinguish between intraspecific competition and interspecific competition.
3. a)
What is predation?
b)
How does predation operate as a density dependent factor?
c)
How does disease operate as a density dependent factor?
d)
What is the “Allee effect”?
4. a)
What is a density independent factor?
b)
What is a “limiting factor”?
c)
What typically happens when a population surpasses the carrying capacity of the environment?
d)
Why do population biologists monitor natural fluctuations in such things as the size and density
of populations?
Read pages 676-687 in your textbook and then answer the following questions.
Interactions within Communities
1. a)
What are FIVE different categories of interactions between species? You may choose to copy
Table 1 from page 677 into your notes.
b)
What is meant by the term “symbiosis”?
c)
What are THREE types of symbiosis? Provide an example of a symbiotic relationship that
involves your organism.
2. a)
b)
What is interspecific competition?
What are two ways in which interspecific competition can occur? Provide an example of each
type of interspecific competition.
3. What are THREE possible results of interspecific competition?
Predation
1. Read the first paragraph of the top of page 681. In your own words, summarize the relationship
between predator and prey populations.
2. Copy Figure 8 on page 681 into your notes. Explain how this figure depicts the changes in
populations of prey species and predator species.
Part 2: Interactive Labs
Do the following on-line labs and submit your answers
1.
http://glencoe.mcgraw-hill.com/sites/dl/free/0078757134/383928/BL_04.html - see the word
document posted on our webpage
2.
Go to: http://www.explorelearning.com/index.cfm?method=cUser.dspLoginJoin
Do the following 2 GIZMOS: Estimating Population Size & Rabbit Population - see the word document
posted on our webpage